The origins of online timer

Mechanical clocks were originally designed with swing or balance-time basis as timers.
The famous timers from that period is, perhaps, the alarm clock, or even the church bell, the bell at the set time prompted an internal mechanism or stroke.

Even in the first half of the 20 Century popular synchronous clocks had often switch contacts.Electromechanical switches for home use are often implemented as an adapter plug and have a switched outlet.

They online timer are driven by a synchronous motor, and is controlled as a Synchronous of the mains frequency. About coding slider can be set, at which time and off.Synchronous clocks have the disadvantage that they remain in power failure.Today online timer there are electronic, battery-quartz or radio controlled models with one relay output.

Almost all of these switches are either so-called seven-day clocks, which allow switching time programming on a certain day, or year time switches, which turn to a certain date.

Yearly timers have also always the functionality of a day time, thus also allowing a switching operation on a particular day of the week regardless of the current date.Timers in switchgear and controls are also fed from the mains. She formerly worked mechanically (train with balance, electric lift) and had a power reserve of a few days.Later was used a quartz movement with a stepper motor, one of the drive wheel train. These watches need a buffer battery to keep running during a power failure can.

Today electronic watches are used (quartz or radio-controlled), which usually have a relay as a switch.Some digital timers can not only preselected times on and off, but pseudo-random switching (eg evenings turn on the light, to the presence of fake) to determine summer and winter time, by synchronizing over the DCF77, or they determine shift points After years time dependent sunrises and sunsets (called Astro function).

Short-term timersShort timer (1 hour) with clockworkShort time switches do not operate according to the absolute time, but always switch one consumer for a preset period of time or delayed or out. Discrete components in controls are referred to as timers.

This includes exposure watches and automatic stairway lighting.Short timers operate mechanically, electro-mechanically connected to a synchronous motor, or electronically with a clock generator and a frequency divider.Previously, they were often operated with a pneumatic delay, a mechanical inhibition or an aerodynamic brake.In purely mechanical short-timers by pressing the delay start a spring mechanism is mounted. This design needs no operating current.Wall clocksA Signaluhr is a timer which at predetermined time points for a certain short duration makes electrical contact. For example, every day at 12 for three seconds clock is triggered a pause signal, such as the gong in a school or the signal for a shift change in a production operation.

A Signaluhr that generates momentum for slave clocks, called master clock. A Funksignaluhr use a radio clock for timing.Comparison of mechanical / digitalDigital time switchesDaily timer with 10steinigem balance-movement and motorized lift for network operation (power reserve 50 hours, built in 1987, VEB Glashütte watch factory DDRProvided with keys and a display, let digital timers accurate and - to any degree of complexity on / off times - depending on the equipment.

You need a battery to store the settings. As electronic timers have a relay, they consume additional power when the consumer (similar to Synchronous-timers).

Through the use of a bistable relay (impulse switch) can reduce the energy requirements are also in the ON state.Mechanical timersAnd the energy requirements of mechanical switches is small (less than 1 watt [1]). You do not need batteries and are easy to use. The switching intervals are at least 15 minutes. On / off intervals can be set intuitively. In case of power interruptions they stop and have to be reset.

They constantly consume power.Previously, there were also mechanical timers with a clockwork motor and an elevator or an electronic / mechanical quartz movement. This had the lowest energy consumption of all timers.Working with an inhibition and a spring plant short timers do not have their own electricity consumption.